Hello,
It may not be easy to treat 
ADHD in kids and teenagers. If ADHD remains incompletely treated, it does a toll on child's self-esteem also & too many times, in a desire to get noticed, get some appreciation, the child engages into undesirable behaviors which are at present your main concern.
There are medications which can be used and include 
methylphenidate or 
atomoxetine. 
As a part of parent-teacher management, we can engage in the token economy, contingency management, role plays, time out, etc. which are taught by 
Psychologist to both the parents & teachers in school.
 Hence, do contact your Psychologist for PTMT; if need further help do revert back to me. 
Hope I have answered your query. Let me know if I can assist you further.
Take care
Regards,
Dr Ivan R. Rommstein, General Surgeon